Control of the anisotropic organization of nanostructured silica-based hybrid materials
Control of the anisotropic organization of nanostructured silica-based hybrid materials
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DOI：
10.1021/cm011180u
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发表时间：
2002-02-01
影响因子：
8.6
通讯作者：
Nobili, M
中科院分区：
文献类型：
--
作者：
Boury, B;Ben, F;Nobili, M
本文关注的影响，在实验条件的变化上观察到的混合材料从六个刚性棒和半刚性的双-trialcoxsilylated前体和一个trisilylate在硅缩聚后的微观组织。不同的溶剂和催化剂的研究表明，双折射性能是高度依赖于这些参数。特别是在碱性催化的情况下，观察到催化剂的剧烈作用，其或多或少能够诱导Si-O-Si键的催化裂解。例如，使用NaOH，可以观察到没有或非常弱的双折射，但是在硅处的缩聚水平更高。总之，微米级组织的最佳实验条件是在THF、DMF、NMF和甲苯中使用HCl或亲核催化剂（F-）。
This paper concerns the effect of changes in experimental conditions on the micrometric-scale organization observed in hybrid materials obtained from six rigid rod and semi-rigid bis-trialcoxsilylated precursors and one trisilylate after polycondensation at silicon. Different solvents and catalysts have been studied showing that birefringence properties are highly dependent on these parameters. A drastic effect of catalyst is observed especially in the case of basic catalysis, which is more or less capable of inducing a catalytic cleavage of the Si-O-Si bond. For instance, with NaOH either no or very weak birefringence can be observed, but the level of polycondensation at silicon is higher. In summary, the best experimental conditions for micrometric-scale organization are the use of HCl or nucleophilic catalysis (F-) in THF, DMF, NMF, and toluene.